If you are already used to pollution ridden images of Beijing and Shanghai, here is something different .. NASA’s terra satellite has now taken pictures of the pollution ridden stretch between the two cities. The Moderate Resolution Imaging Spectroradiometer seems to have distinguished perfectly between clouds and pollution.
The brightest areas are clouds and the dim ones, clouds. Rudolf Husar, director of the Centre for Air Pollution Impact and Trend Analysis at Washington University says that the fog has a smooth surface on top that distinguishes it from mid- and high-level clouds that are more textured and have distinct shadows on their edge.
He adds that if there is a significant haze layer on top of the fog, it appears brownish. In China’s case the pollution is trapped in the shallow winter boundary layer of a few hundred meters. But he says we should be concerned because it is not common that the pollution should spread so far.
But US embassies in both the cities say that the pollution levels I these cities were real high standing at 480 and 355 micrograms per cubic metres in the air. This is way above the levels prescribed by World Health Organization which seals of the limits at 25.
An airborne particle of more than 2.5 microns is dangerous as it can enter the passages of the human lungs easily. Meanwhile, an AQI above 300 is hazardous to even extremely healthy human beings. The Chinese authorities have halted construction and have asked he children to stay indoors to get away from the smog.